SECONDARY BATTERY

摘要

Provided is a secondary battery which is capable of more reliably cutting off current by increasing a deformation amount of a member, which is deformed by a rise of an internal pressure of a battery container and cuts off current. The secondary battery is provided with a current cut-off mechanism 50 in a current path between an external terminal 20A and an electrode 41 inside a battery container 10. The current cut-off mechanism 50 is accommodated in the battery container 10, and is provided with a diaphragm 5 connected to the external terminal 20A and a current collector 30A connected to the electrode 41. The diaphragm 5 is disposed on an outer side of the battery container 10 than the current collector 30A and has a convex shape toward an inside of the battery container 10. The current collector 30A includes a concave portion 33b on a surface facing the outer side of the battery container 10, and the diaphragm 5 is bonded to the concave portion 33b.